8S0 
E Q U 
fecond objeft ; repeat this operation till no error remain; 
then fet the hour circle exactly to 12 hours, the declina¬ 
tion circle remaining at 90 0 as before; and if the centre 
of the crofs-hairs do not cover the laft object fixed on, 
fet it to that object by the two remaining fnrall fcrevvs at 
the eye-end of the large tube, and then the line of colli- 
mation will be parallel to the brafs rod. For rectifying 
the nonius of the declination and equatorial circles, lower 
the telefcope as many degrees, &c. below o° on the de¬ 
clination femicircle as are equal to the complement of 
the latitude; then elevate the polar axis till the bubble 
be horizontal; and thus the equatorial circle will be ele¬ 
vated to the co-latitude of the place : fet this circle to 6 
hours; adjuft the level by the pinion of the declination 
circle; then turn the equatorial circle exadtly 12 hours 
from the laft pofition ; and if the level be not right, cor¬ 
rect one half of the error by the equatorial circle, and 
the other half by the declination circle: then turn the 
equatorial circle back again exadtly 12 hours from the 
laft pofition ; and if the level be Hill wrong, repeat the 
corredtion as before, till it be right, when turned to 
either pofition: that being done, fet the nonius of the 
equatorial circle exadtly to 6 hours, and the nonius of the 
declination circle exadtly to o°. 
The chief ufes of this equatorial are, Firft, To find the 
meridian by one obfervation only : for this purpofe, ele¬ 
vate the equatorial circle to the co-latitude of the place, 
and fet the declination femicircle to the fun’s declination 
for the day and hour of the day required ; then move the 
azimuth and hour circles both at the fame time, either in 
the fame or contrary diredtion, till you bring the centre 
of the crofs-hairs in the telefcope exadtly to cover the 
centre of the fun; when that is done, the index of the 
hour circle will give the apparent or folar time at the 
inftant of obfervation ; and thus the time is gained, though 
the fun be at a diftance from the meridian ; then turn the 
hour circle till the index points precifely at 12 o’clock, 
and lower the telefcope to the horizon, in order to ob- 
ferve fome point there in the centre of the glafs ; and that 
point is the meridian mark, found by one obfervation 
only. The belt time for this operation is three hours be¬ 
fore, or three hours after, twelve at noon.—Secondly, To 
point the telefcope on a ftar, though not on the meridian, 
in full day-light. Having elevated the equatorial circle 
to the co-latitude of the place, and fet the declination fe- 
micircle to the ftar’s declination, move the index of the 
hour circle till it (hall point to the precife time at which 
the ftar is then diftant from the meridian, found in the 
tables of the right afcenfion of the ftars, and the ftar will 
then appear in the glafs.—Befides thefe ufes, peculiar to 
this inftrument, it may alfo be applied to all the purpofes 
to which the principal aftronomical inftruments are ap- 
applied ; fuch as a tranfit inftrument, ajjuadrant, and an 
equal-altitude inftrument. 
EQUE'A, a town of Africa, on the Gold Coaft. 
E'QjJERY, or Equerry, f [ecuyer, Fr.] Anofficer 
who has the care and management of the horfes of a king 
or prince. Stables for horfes, furnifhed with all con¬ 
veniences. The lodging places or apartments of the 
equerries or grooms. 
E'QUES, f. the Knight; a new genus of fifties in 
Block’s fyftem ; for the fpecies of which fee Ch^todon. 
EQUE'STRI AN, adj. [ equejlris , Lat.] Being on horfe- 
back.—An equeftrian lady appeared upon the plains. Spec¬ 
tator .—.Skilled in horfemanfhip. Belonging to the fecond 
rank in Rome. 
Equestrian Games, among the Romans, horfe-races, 
of which there were five kinds: the prodromus or plain 
horfe-race, the chariot-race , the decurfory-race about funeral 
piles, the ludifevirales , and the ludi neptunales. 
Equestrian Order, the knights or equites of an¬ 
cient Rome. 
EQU E'STRIAN STATUE, in fculpture, the figure 
of a perfon on horfeback,—See the article Sculpture. 
EQU 
E QU I AN'GUL AR, adj. in mathematics,a figure that has 
all its angles equal among themfelves ; as the fquare, and 
all the regular figures. An equilateral figure infcribed 
in a circle, is always equiangular. But an equiangular 
figure infcribed in a circle, is not always equilateral, ex¬ 
cept when it has an odd number of Tides : If the Tides be 
of an even number, then they may either be all equal, or 
elTe half of them will always be equal to each other, and 
the other half to each other, the equals being placed al¬ 
ternately. Equiangular, is alfo faid of any two figures of 
the fame kind, when each angle of the one is equal to a 
correfponding angle in the other, whether each figure, 
feparately confidered in itfelf, be an equiangular figure or 
not, that is, having all its angles equal to each other. 
Thus, two triangles are equiangular to each other, if, 
ex. gr. one angle in each be of 30°, a fecond angle in each 
°f f°°» and the third angle of each equal to 100 degrees. 
Equiangular triangles have not their like Tides neceftarily 
equal, but only proportional to each other; and fuch tri¬ 
angles are always fimilar to each other. 
EQUICU'LUS or Equus Minor, a conftellation of 
the northern hemifphere. See Equuleus. 
EQUICRU'RAL, or Equicrure, adj. [xquus and 
crus, Lat.] Having legs of an equal length, and longer 
than the bafe ; ifofceles.—An equicrure triangle goes upon 
a certain proportion of length, and breadth. Digby. —We 
fuccefiively draw lines from angle to angle, until feven 
equicrural triangles be defcribed. Brown. 
EQUIDIF'FERENT, adj. in arithmetic, belonging to 
a feries of four quantities in which there is the fame dif¬ 
ference between the firft and fecond as between the third 
and fourth. 
EQUI DISTANCE, f. [from equidijlant .] The ftate 
of being equally diftant. 
EQUIDISTANT, adj. [equus and dijlans, Lat.] At 
the fame diftance.—The fix ftars are not all placed in the 
fame concave fuperficies, and equidijlant from us, as they 
feem to be. Ray. 
EQ^JIDIS'TANTLY, adv. At the fame diftance.— 
The liver, feated on the right fide, by the fubclavian di- 
vifion cquidijlantly communicates unto either arm. Brown. 
EQUIFO'RMITY, J. \_<?quus and forma, Lat.] Uni. 
form equality.—No diverfity or difference, but a fimpli- 
city of parts and equiformity of motion. Brown. 
EQUILATERAL, adj. \_equus and latus, Lat.] Having 
all fides equal.—Circles or fquares, or triangles equilateral, 
which are all figures of equal lines, can differ but in 
greater or leffer. Bacon. 
To EQUILI'BRATE, v. a. To balance equally; to 
keep even with equal weight on each fide.—The bodies 
of fifties are equilibrated with the water in which they 
fwim. Arbutknot. 
EQUILIBRATION,y. Equipoife; the adt of keep, 
ing the balance even.—In fo great a variety of motions, 
as running, leaping, and dancing, nature’s laws of equili¬ 
bration are obferved. Derham. 
EQUILIBRIUM, f. [Lat.] Equipoife; equality of 
weight,—Equality of evidence, motives, or powers of 
any kind.—Health confifts in the equilibrium between thofe 
two powers, when the fluids move fo equally that they 
don’t prefsupon the folids with a greater force than they 
can bear. Arbuthnot.—Equilibrium in folid bodies forms a 
confiderable part of the fcience of ftatics ; and equilibrium 
of fluids a confiderable part of the dodtrine of hydroftatics. 
Hutton. 
It is in equilibria 
If deities defcend or no ; 
Then let th’ affirmative prevail. 
As requifites to form my tale. Prior . 
EQUIMULTIPLES, f. in arithmetic and geometry, 
numbers or quantities multiplied by one and the fame 
number or quantity. Hence, equimultiples are always in 
3 the 
